设计了一种由一个槽型腔和两个波导耦合构建的金属-介质-金属 (MDM) 滤波器，并利用时域有限差分法对该结构进行了仿真研究，分析了主要结构参数对滤波器传输特性的影响。研究发现：纵向位移L_d对传输特性有重要影响, 会导致新的谐振峰出现; 在一定范围内, 槽腔宽度W_c 的增加使得透射峰增加并且更均匀地分布在600～1500 nm范围内。通过参数优化最终设计了分布于550、730、920、1330 nm波段窗口附近的多通道滤波器，该设计透射峰窄、品质因子良好，且结构简单、易于集成、制作方便，能够很好地运用在波分复用系统及光通信中。

A metal-dielectric-metal (MDM) filter is designed which is composed of a slot cavity and two waveguides. The influence of main structure parameters on the transmission characteristics of the filter is analyzed in detail using the finite-difference time-domain (FDTD) method. It is found that the lateral displacement L_d has a significant impact on transmission properties of the filter,which will lead to the appearance of new resonance peaks. In addition, it is shown that the increase of the cavity width W_c will not only make the number of transmission peaks increase, but also make the transmission peaks distribute more uniformly in the range from 600 nm to 1500 nm within limits. Through parameter optimization, a multi-channel filter distributed near the 550, 730, 920 and 1330 nm wavelength windows in optical communication systems is designed. The design has the advantages of narrow transmission peak, good quality factor, simple structure, easy integration and easy fabrication, which can be well used in wavelength-division multiplexing system and optical communication.